The present invention relates to a rail bed maintenance apparatus and, more specifically, to an apparatus for removing and replacing railway cross ties from a rail bed.
Various machines are known for removing and replacing railway cross ties from a rail bed for maintenance purposes. These machines have included apparatus for sawing or otherwise severing the tie in its mid-season and for withdrawing the so-severed halves, for connecting flexible cables to the tie to pull it from the track, and more sophisticated machines that include hydraulically operated booms for engaging an end of the tie to apply a thrust force that pushes the tie laterally outward from the one side of the rail bed and various pulling machines for manually gripping the end of the tie and pulling the so-gripped tie from the rail bed. In general, the known machines provide acceptable levels of performance although these machines possess certain disadvantages or drawbacks that are related to their structural arrangements or method of operation. For those machines that sever the tie prior to its withdrawal, it is necessary to manipulate a severing device such as a saw blade or opposed cutting blades to effect the severing operation. In the course of the operation of these severing machines, the cutting blades must be resharpened or replaced periodically which, of course, adds to the expense of the removal and replacement operation. Those machines which push or pull the tie from the rail bed are generally quite large and some are also restricted to removing and replacing rail ties from one side of the rail bed or the other. In those cases where it is desired to pull or push a tie from either side of the rail bed, it is often necessary in some machines to reverse the orientation of all or a major portion of the machine components.